1. Field of the Invention
The present invention generally relates to a standalone input device or keyboard with a planar top surface with no openings or cracks to a personal computer (PC), control panels for operating equipment, and data input in rugged environments where an internal light beam is emitted out through an optical opening into bright sunlight ambient or total darkness, when a finger is present the finger encompasses the opening blocking out the ambient influence on a detector, the emitter is turned on reflecting the emitted unabated beam off the finger to a detector indicating a finger is present.
2. Description of the Prior Art
Optical keyboards some use techniques to reduce the ambient effect on finger detection but when used in bright sunlight where bright sunlight saturates the photodiodes nothing stops this saturation unless under an awning or the like, and in total darkness where the user cannot see the key indicia, or lack a planer top surface to be easily cleaned in industrial, atomic and medical environments, some of which that try follow hereto.
U.S. Pat. No. 6,175,679 Veligdan et al shows a keyboard with stacked waveguides to detect a finger.
U.S. Pat. No. 4,629,884 Bergstom with a radiation propagating prism to detect a finger.
U.S. Pat. No. 4,701,747 Isterwood shows a keyboard that has a light beam from a LED that reflects the light beam to a photodiode when a finger is present with a noise and ambient electronic rejection technique.
U.S. Pat. Nos. 5,378,069, 5,577,848, 5,605,406, 5,707,160, 5,785,439, Bowen shows keyboards that detects an users finger by blocking an X and Y optical beam.